Recent imaging devices, for example a digital camera are provided with a function for preventing a camera shake. For example, a camera disclosed in Japanese Patent Laid-open Publication No. 05-249529 includes a camera shake correction lens that is movable in a plane perpendicular to an optical axis, a lens position detector for detecting a decentering amount of the camera shake correction lens decentered from the optical axis, and a display for displaying a direction in/to which the camera should be moved so that the decentering amount becomes zero. On releasing, the camera shake correction lens is set not near an end of a correcting range and a camera shake is suppressed. Moreover, a video camera disclosed in Japanese Patent Laid-open Publication No. 05-137048 detects a motion vector by the representative point matching method and corrects a camera shake based on the motion vector.
The camera disclosed in the Japanese Patent Laid-open Publication No. 05-249529 is capable of correcting the camera shake, but disadvantageously it is not capable of detecting and correcting a subject shake (shake due to motion of the subject). The video camera disclosed in the Japanese Patent Laid-open Publication No. 05-137048 is capable of detecting the subject shake, but disadvantageously it is not capable of sufficiently correcting the camera shake because of delay of the shake detection resulting from that the motion is estimated after an image is retrieved.